/Engine/Plugins/Runtime/GeometryProcessing/Source/DynamicMesh/Public/Parameterization/DynamicMeshUVEditor.h
Compute an oriented UV-space bounding box for the given Triangles, and then rotate the UVs such that the box is aligned with the X axis. The UV-space box is found by computing the 2D Convex Hull and then finding the hull edge that results in the minimal box.
bool AutoOrientUVArea ( const [TArray](API\Runtime\Core\Containers\TArray)< int32 > & Triangles )